With the gradual population of wearable application devices, such as smart glasses, smart phone, et cetera, the demands for flexible display in the display industry have constantly increased.
An Organic Light Emitting Diodes Display (OLED) possesses properties of self-illumination, no required back light, being ultra thin, wide view angle, fast response and etc., and accordingly has the nature advantage of flexible display. However, the OLED industry remains the extremely high bar of technology. The difficulty of the manufacture process is high. The yield is low and the cost, the selling prices are high. These drawbacks get in way of wide applications of the OLED.
Liquid Crystal Display (LCD) is the most widely used display devices in the market. The production technology is quite mature. The yield of the production is high. The cost is relatively low and the acceptance is high in the market.
Normally, the liquid crystal display comprises a shell, a liquid crystal display panel located in the shell and a backlight module located in the shell. The liquid crystal panel comprises a color filter (CF) substrate, a thin-film transistor (TFT) array substrate and a liquid crystal layer filled between the two substrates. Transparent electrodes are formed on inner sides of the CF substrate and the TFT substrate. The liquid crystal display performs control to the orientation of the liquid crystal molecules in the liquid crystal layer with an electric field to change the polarization state of the light. The objective of displaying is achieved with the polarizer to realize the transmission and the obstruction of the optical path.
At present, most of LCD productions, and particularly the large scale LCDs, utilize photo spacer (PS) to control a cell gap. FIG. 1 is a structural diagram of a liquid crystal panel according to prior art in a plane state. The liquid crystal material in the liquid crystal layer 300 is a fluid, which is flowable. The TFT substrate 100 and the CF substrate 200 are supported by the photo spacers 400 arranged between the two substrates. As shown in FIGS. 3 and 4, the photo spacers 400 are generally formed with a photolithographic process in a specific area in a display side, which is commonly in a black matrix (BM) 201 for maintaining the thickness and the stability of the liquid crystal layer 300.
Such photo spacers 400 cannot stop the liquid crystal material to flow in the entire liquid crystal panel. Although the liquid crystal panel shown in FIG. 1 can satisfy the display evenness demands when the liquid crystal panel in a plane state. The cell gap of the liquid crystal layer 300 is kept around the design value, and the cell gap is more even. However, after the liquid crystal panel previously in the plane state is bent, as shown in FIG. 2, the TFT substrate 100 and the CF substrate 200 are misaligned and the curvatures do not match. The liquid crystal material is pressed and flowing. Ultimately, it results in that the uneven cell gap at various positions of the liquid crystal layer. The thickness of the liquid crystal layer 300 is uneven to result in abnormal displaying.
The common liquid crystal panels in the main market can be categorized in three types, which are respectively twisted nematic/super twisted nematic (TN/STN) types, in-plane switching (IPS) type and vertical alignment (VA) type. Although the principles of liquid crystal display adjustment may be of differences, the basic structures of these three types of liquid crystal panel are similar. The displaying property and the cell gap of the liquid crystal layer are closely related. Whether the cell gap of the liquid crystal layer is even has direct influence on the displaying effect. Changing the cell gap of the liquid crystal layer will affect the displaying brightness, contrast, response speed, etc. of the liquid crystal panel. Therefore, improvement is necessary to the known liquid crystal panel to solve the issue of uneven cell gap caused by a bent liquid crystal layer for making the liquid crystal panel adaptable for flexible displaying.